The invention relates to novel deoxycyclodepsipeptides, to processes for their preparation and to their use for controlling parasites, in particular helminths, in veterinary and human medicine.
Various cyclodepsipeptides having antiparasitic activity are described in the literature. EP-A 382 173 discloses a cyclooctadepsipeptide designated PF 1022. EP-A 626 376, EP-A 634 408 and EP-A 718 293 disclose further 24-membered cyclodepsipeptides. Their anthelmintic activity is not in all cases satisfactory.
The invention relates to novel deoxycyclodepsipeptides which are prepared from cyclodepsipeptides having 24 ring members which are constructed from alternating xcex1-aminocarboxylic acids and (xcex1-hydroxycarboxylic acids, by complete or partial chemoselective reduction of the carbonyl groups of the amide function to give methylene groups using suitable reduction processes, and to mixtures and derivatives thereof.
The cyclodepsipeptides employed as starting materials are constructed from alternating 4 xcex1-aminocarboxylic acids and 4 xcex1-hydroxycarboxylic acid-units.
xcex1-Aminocarboxylic acids are natural or synthetic amino acids which may be identical or different. They may be N-alkylated, i.e. substituted by a straight-chain or branched C1-4-alkyl group, preferably a methyl group, which for its part may also be substituted.
xcex1-Hydroxycarboxylic acids are natural and synthetic 2-hydroxycarboxylic acids which may be identical or different.
Complete or partial chemoselective reduction means that one or more amidic carbonyl groups (Cxe2x95x90O adjacent to N) are reduced without the ester carbonyl groups (Cxe2x95x90O adjacent to O) in the cyclodepsipeptide skeleton being attacked.
The reduction is carried out either directly or in a multi-stage process, depending on the reducing agent chosen.
Complete or partial reduction means that, for example, in an octadepsipeptide having 4 amidic carbonyl groups, all 4 of the carbonyl groups in question or 1 to 3 of these carbonyl groups are reduced.
The reduction generally yields mixtures of the deoxydepsipeptides in varying degrees of reduction. The individual components are present in varying proportions, depending on the stoichiometry and the kind of reduction process. Homogeneous deoxydepsipeptides are obtained from the mixtures by employing the customary physical or chemical separation processes.
The products obtained in the reduction can be converted chemically into further derivatives.
The deoxycyclodepsipeptides according to the invention can be characterized by the formula (I): 
in which
Cxe2x95x90X1, Cxe2x95x90X2, Cxe2x95x90X3 and Cxe2x95x90X4 independently of one another each represent one of the groups CO, CS or CH2, where at least one of these groups represents CH2,
R1 and R2 independently of one another each represent hydrogen, alkyl, hydroxymethyl or alkoxymethyl,
R3 and R4 independently of one another each represent alkyl or represent phenyl or benzyl, each of which is optionally mono- or polysubstituted by radicals W,
where
W represents halogen, nitro, cyano, carbonyl, alkoxycarbonyl, alkyl, xe2x80x94CH(R13)NR14R15, alkenyl, alkoxycarbonylalkenyl, alkynyl, alkoxy-carbonylalkynyl, hydroxyl, alkoxy, alkoxyalkoxy, alkoxyalkoxyalkoxy, dialkylaminoalkoxy, respectively optionally substituted aryl, arylalkyl, aryloxy or arylmethoxy, represents heterocyclylmethoxy, xe2x80x94NR16R17, xe2x80x94SO2xe2x80x94NR R16R17, xe2x80x94SR18, xe2x80x94S(O)R18 or xe2x80x94S(O)2R18,
R13 represents hydrogen or carboxyl,
R14 represents hydrogen, alkyl, optionally halogen-substituted alkylcarbonyl or benzoyl or
R13 and R14 together represent a radical xe2x80x94(CH2)nxe2x80x94COxe2x80x94, where n=2, 3 or 4,
R15 represents hydrogen, alkyl, optionally halogen-substituted alkylcarbonyl or benzoyl or
R14 and R15 together represent a radical xe2x80x94(CH2)oxe2x80x94COxe2x80x94, where o=3, 4 or 5, represent a diacyl radical of a C4-C6-dicarboxylic acid or represent optionally halogen-substituted phthaloyl,
R16 represents hydrogen, optionally halogen-, hydroxyl- or alkoxy-substituted alkyl, represents heterocyclylmethyl, formyl, alkylcarbonyl or optionally substituted arylmethyl or benzoyl or represents the radical xe2x80x94COxe2x80x94CR19R20xe2x80x94NR21R22 and
R17 represents hydrogen, optionally halogen-, hydroxyl- or alkoxy-substituted alkyl, represents heterocyclylmethyl, alkylcarbonyl or optionally substituted arylmethyl or benzoyl,
R16 and R17 together represent optionally substituted phthaloyl or, together with the linking nitrogen atom, represent an optionally substituted mono- or polycyclic, optionally bridged and/or spirocyclic, saturated or unsaturated heterocycle which may contain one to 3 further hetero atoms from the group consisting of nitrogen, oxygen and sulfur,
R18 represents alkyl or optionally substituted phenyl or benzyl,
R19 represents one of the radicals of a natural or synthetic xcex1-amino acid, where functional groups may optionally be protected,
R20 represents hydrogen, alkyl or phenyl,
R19 and R20 together represent xe2x80x94(CH2)pxe2x80x94, where p=2, 3, 4 or 5, or represent xe2x80x94(CH2)2xe2x80x94NR23xe2x80x94(CH2)2xe2x80x94, where R23 represents alkyl, phenyl or benzyl,
R21 represents hydrogen or alkyl,
R19 and R21 together represent xe2x80x94(CH2)3xe2x80x94 and xe2x80x94(CH2)4xe2x80x94 and
R22 represents hydrogen or a protective group known from peptide chemistry, such as acetyl, tert-butoxy carbonyl (Boc), benzyl-oxycarbonyl (Cbz) or benzyl (Bzl),
R5, R6, R7 and R8 independently of one another each represent hydrogen, optionally amino- or hydroxyl-substituted alkyl, represent mercaptomethyl, methylthioethyl, carboxymethyl, carboxyethyl, carbamoylmethyl, carbamoylethyl, guanidinopropyl, represent optionally amino-, nitro-, halogen-, hydroxyl- or methoxy-substituted phenyl or benzyl, represent naphthylmethyl, indolylmethyl, imidazolylmethyl, triazolylmethyl or pyridylmethyl, where functional groups may optionally be protected, and
R9, R10, R11 and R12 independently of one another each represent hydrogen or optionally substituted C1-4-alkyl.
The protective groups known from peptide chemistry are listed, for example, in T. W. Greene, P. G. M. Wuts, Protective Groups in Organic Synthesis, 2nd Ed., John Wiley and Sons, New York 1991.
The configuration at the chiral carbons is immaterial, i.e. the compounds of the formula (I) according to the invention are constructed from D- and/or L-configured amino acids and hydroxycarboxylic acids. The invention provides the pure stereoisomers and mixtures thereof. The compounds are preferably constructed from alternating D-hydroxycarboxylic acids and L-amino acids.
The invention furthermore provides a process for preparing the compounds according to the invention, characterized in that cyclodepsipeptides which have been prepared by fermentation or synthetically and which have 24 ring members
a) are reduced with borane (boron hydride) or complex hydrides in the presence of metal salts, or
b) are reacted with a sulfurizing agent and subsequently reduced with complex hydrides in the presence of metal salts and
the compounds according to the invention obtained by one of the processes a) or b) are optionally derivatized further.
Furthermore, it has been found that the compounds according to the invention are outstandingly suitable for controlling helminths in human and veterinary medicine.
The formula (I) given above defines preferred compounds according to the invention.
Cxe2x95x90X1, Cxe2x95x90X2, Cxe2x95x90X3 and Cxe2x95x90X4 independently of one another each preferably represent one of the groups CO, CS or CH2, where at least one of these groups represents CH2.
R1 and R2 independently of one another each preferably represent hydrogen, C1-C6-alkyl, hydroxymethyl or C1-C6-alkoxymethyl.
R3 and R4 independently of one another each preferably represent C1-C6-alkyl or phenyl or benzyl, each of which is optionally mono- or disubstituted by a radical W.
R5, R6, R7 and R8 independently of one another each preferably represent hydrogen, methyl, iso-propyl, iso-butyl, sec-butyl, hydroxymethyl, 1-hydroxyethyl, mercaptomethyl, 2-methylthioethyl, 3-aminopropyl, 4-aminobutyl, carboxymethyl, 2-carboxyethyl, carbamoylmethyl, 2-carbamoylethyl, 3-guani-dinopropyl, phenyl, benzyl, 4-hydroxybenzyl, 4-methoxybenzyl, 2-nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-aminobenzyl, 3-aminobenzyl, 4-aminobenzyl, 3,4-dichlorobenzyl, 4-iodobenzyl, (xcex1-naphthylmethyl, xcex2-naphthylmethyl, 3-indolylmethyl, 4-imidazolylmethyl, 1,2,3-triazol-1-yl-methyl, 1,2,4-triazol-1-yl-methyl, 2-pyridylmethyl or 4-pyridylmethyl, where functional groups may optionally be protected.
R9, R10, R11 and R12 independently of one another each preferably represent hydrogen, methyl or ethyl.
W preferably represents halogen, nitro, cyano, carbonyl, C1-C6-alkoxycarbonyl, C1-C6-alkyl, xe2x80x94CH(R13)NR14R15, C2C6-alkenyl, C1-C6-alkoxycarbonyl-C2-C4-alkenyl, C2-C6-alkynyl, C1-C6-alkoxycarbonyl-C2-C4-alkynyl, hydroxyl, C1-C6-alkoxy, C1-C6-alkoxy-C1-C6-alkoxy, C1-C6-alkoxy-C1-C6-alkoxy-C1-C6-alkoxy, di-(C1-C6-alkyl)-amino-C2-C6-alkoxy, represents phenyl, benzyl, phenoxy or benzylmethoxy, each of which is optionally mono- to trisubstituted independently of one another by halogen, nitro, cyano, C1-C4-alkyl, C1-C4-alkoxy, C1-C4-halogenoalkoxy, hydroxyl or amino, represents heterocyclylmethoxy having a 5- to 6-membered monocycle or 8- to 10-membered bicycle having 1 to four hetero atoms selected from 1 to 4 nitrogen atoms, 1 to 2 oxygen and/or 1 to 2 sulfur atoms, represents xe2x80x94NR16R17, xe2x80x94SO2xe2x80x94NR16R17, xe2x80x94SR18, xe2x80x94S(O)R18 or xe2x80x94S(O)2R18.
R13 preferably represents hydrogen or carboxyl.
R14 preferably represents hydrogen, C1-C6-alkyl, optionally fluorine- or chlorine-substituted C1-C6-alkylcarbonyl or benzoyl.
R13 and R14 together also preferably represent a radical xe2x80x94(CH2)nxe2x80x94COxe2x80x94, where n=2, 3 or 4.
R15 preferably represents hydrogen, C1-C6-alkyl, C1-C6-alkylcarbonyl or benzoyl.
R14 and R15 together also preferably represent a radical xe2x80x94(CH2)oxe2x80x94COxe2x80x94, where o=3, 4 or 5, represent a diacyl radical of a C4-C6-dicarboxylic acid or represent optionally halogen-substituted phthaloyl.
R16 preferably represents hydrogen, optionally halogen-, hydroxyl- or C1-C6-alkoxy-substituted C1-C6-alkyl, represents heterocyclylmethyl having a 5- to 6-membered monocycle or 8- to 10-membered bicycle having 1 to four hetero atoms selected from 1 to 4 nitrogen atoms, 1 to 2 oxygen and/or 1 to 2 sulfur atoms, represents formyl, C1-C6-alkylcarbonyl or represents benzyl or benzoyl, each of which is optionally mono- to trisubstituted independently of one another by halogen, nitro, cyano, C1-C4-alkyl or C1-C4-alkoxy, or represents the radical xe2x80x94COxe2x80x94R19R20xe2x80x94NR21R22.
R17 preferably represents hydrogen, optionally halogen-, hydroxyl- or C1-C6-alkoxy-substituted C1-C6-alkyl, represents heterocyclylmethyl having a 5- to 6-membered monocycle or 8- to 10-membered bicycle having 1 to four hetero atoms selected from 1 to 4 nitrogen atoms, 1 to 2 oxygen and/or 1 to 2 sulfur atoms, represents C1-C6-alkylcarbonyl or represents benzyl or benzoyl, each of which is optionally mono- to trisubstituted independently of one another by halogen, nitro, cyano, C1-C4-alkyl or C1-C4-alkoxy.
R16 and R17 together also preferably represent halogen-, nitro-, cyano-, C1-C4-alkyl- or C1-C4-alkoxy-substituted phthaloyl or, together with the linking nitrogen atom, represent an optionally halogen-, C1-C4-alkyl- or C1-C4-alkoxy-substituted and optionally N-acylated monocyclic heterocycle having 3 to 8 ring members or bicyclic heterocycle having 7 to 11 ring members which is optionally bridged and/or spirocyclic, optionally condensed with one or two carbocyclic ring systems, saturated or unsaturated and may contain 1 to 3 further hetero atoms from the group consisting of 1 to 3 nitrogen atoms, 1 oxygen atom and 1 sulfur atom.
R18 preferably represents methyl, ethyl or represents phenyl or benzyl, each of which is optionally mono- or disubstituted independently of one another by fluorine, chlorine, nitro, methyl, trifluoromethyl or methoxy.
R19 preferably represents hydrogen, optionally amino- or hydroxyl-substituted C1-C4-alkyl or represents mercaptomethyl, methylthioethyl, carboxymethyl, carboxyethyl, carbamoylmethyl, carbamoylethyl, guanidinopropyl or represents optionally amino-, nitro-, halogen-, hydroxyl- or methoxy-substituted phenyl or benzyl or represents naphthylmethyl, indolylmethyl, imidazolylmethyl, triazolylmethyl or pyridylmethyl, where functional groups may optionally be protected.
R20 preferably represents hydrogen, C1-C4-alkyl or phenyl.
R19 and R20 together also preferably represent xe2x80x94(CH2)pxe2x80x94, where p=2, 3, 4 or 5, or represent xe2x80x94(CH2)2xe2x80x94NR23xe2x80x94(CH2)2xe2x80x94, where R23 represents C1-C4-alkyl, phenyl or benzyl.
R21 preferably represents hydrogen or C1-C4-alkyl.
R19 and R21 together also preferably represent xe2x80x94(CH2)3xe2x80x94 and xe2x80x94(CH2)4xe2x80x94.
R22 preferably represents hydrogen or a protective group known from peptide chemistry, such as acetyl, tert-butoxycarbonyl, benzyloxycarbonyl or benzyl.
Cxe2x95x90X1, Cxe2x95x90X2, Cxe2x95x90X3 and Cxe2x95x90X4 independently of one another each particularly preferably represent one of the groups CO, CS or CH2, where at least one of these groups represents CH2.
R1 and R2 independently of one another each particularly preferably represent hydrogen, C1-C4-alkyl, hydroxymethyl or C1-C4-alkoxymethyl.
R3 and R4 independently of one another each particularly preferably represent phenyl or benzyl, each of which is optionally substituted by a radical W.
R5, R6, R7 and R8 independently of one another each particularly preferably represent methyl, iso-propyl, iso-butyl, sec-butyl, hydroxymethyl, benzyl, 4-hydroxy-benzyl, where hydroxyl groups may optionally be protected.
R9, R10, R11 and R12 independently of one another each particularly preferably represent hydrogen, methyl.
W particularly preferably represents fluorine, chlorine, bromine, iodine, nitro, cyano, carbonyl, C1-C4-alkoxycarbonyl, C1-C4-alkyl, xe2x80x94CH(R13)NR14R15, C2-C6-alkenyl, C1-C4-alkoxycarbonyl-C2-C4-alkenyl, C2-C4-alkenyl, C1-C4-alkoxycarbonyl-C2-C4-alkynyl, hydroxyl, C1-C4-alkoxy, C1-C4-alkoxy-C1-C4-alkoxy, C1-C4-alkoxy-C1-C4-alkoxy-C1-C4-alkoxy, di-(C1-C4-alkyl)-amino-C2-C4-alkoxy, represents phenyl, benzyl, phenoxy or benzylmethoxy, each of which is optionally mono- or disubstituted independently of one another by fluorine, bromine, nitro, cyano, C1-C4-alkyl, fluorine- and/or chlorine-substituted methyl or ethyl, C1-C4-alkoxy, trifluoromethoxy, hydroxyl or amino, represents furylmethoxy, benzofurylmethoxy, thienylmethoxy, pyrrolylmethoxy, indolylmethoxy, imidazolylmethoxy, pyridylmethoxy, xe2x80x94NR16R17 or xe2x80x94SO2xe2x80x94NR16R17.
R13 particularly preferably represents hydrogen or carboxyl.
R14 particularly preferably represents hydrogen, C1-C4-alkyl, benzoyl or C1-C4-alkylcarbonyl which is optionally mono- to trisubstituted by fluorine or chlorine.
R13 and R14 together also particularly preferably represent a radical xe2x80x94(CH2)nxe2x80x94COxe2x80x94, where n=2, 3 or 4.
R15 particularly preferably represents hydrogen or methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl.
R14 and R15 together also particularly preferably represent a radical xe2x80x94(CH2)oxe2x80x94COxe2x80x94, where o=3, 4 or 5, represent a diacyl radical of a C4-C6-dicarboxylic acid or represent phthaloyl which is optionally mono- or polysubstituted by chlorine or fluorine.
R16 particularly preferably represents hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, represents methyl, ethyl or n-propyl, each of which is monosubstituted by chlorine, bromine, hydroxyl, methoxy or ethoxy, represents furylmethyl, benzofurylmethyl, thienylmethyl, pyrrolylmethyl, indolylmethyl, imidazolylmethyl, pyridylmethyl, represents formyl, C1-C4-alkylcarbonyl or represents benzyl or benzoyl, each of which is optionally mono- or disubstituted independently of one another by fluorine, chlorine, bromine, iodine, nitro, cyano, C1-C4-alkyl, or C1-C4-alkoxy, or represents the radical xe2x80x94COxe2x80x94CR19R20xe2x80x94R21R22.
R17 particularly preferably represents hydrogen or, depending on R16, an identical radical from the group: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, methyl, ethyl or n-propyl which are monosubstituted by chlorine, bromine, hydroxyl, methoxy or ethoxy, represents furylmethyl, benzofurylmethyl, thienylmethyl, pyrrolylmethyl, indolylmethyl, imidazolylmethyl, pyridylmethyl or benzyl which is optionally mono- or disubstituted independently of one another by fluorine, chlorine, bromine, iodine, nitro, cyano, C1-C4-alkyl or C1-C4-alkoxy.
R16 and R17 together also particularly preferably represent phthaloyl which is optionally mono- to tetrasubstituted by fluorine, chlorine or methyl and/or mono- or disubstituted by bromine, nitro, cyano, C2-C4-alkyl or methoxy, or, together with the linking nitrogen atom, represent an optionally fluorine-, chlorine-, methyl-, ethyl-, n-propyl-, isopropyl-, methoxy- or ethoxy-substituted and optionally C1-C4-alkylcarbonyl-N-acylated monocyclic heterocycle having 3 to 8 ring members or bicyclic heterocycle having 7 to 11 members which is optionally bridged and/or spirocyclic, optionally condensed with one or two carbocyclic ring systems, saturated or unsaturated and may contain 1 to 3 further hetero atoms from the group consisting of 1 to 3 nitrogen atoms, 1 oxygen atom and 1 sulfur atom.
R19 particularly preferably represents hydrogen, methyl, iso-propyl, iso-butyl, sec-butyl, hydroxymethyl, 1-hydroxyethyl, mercaptomethyl, 2-methylthioethyl, 3-aminopropyl, 4-aminobutyl, carboxymethyl, 2-carboxyethyl, carbamoylmethyl, 2-carbamoylethyl, 3-guanidinopropyl, phenyl, benzyl, 4-hydroxybenzyl, 4-methoxybenzyl, 2-nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-aminobenzyl, 3-aminobenzyl, 4-aminobenzyl, 3,4-dichlorobenzyl, 4-iodobenzyl, (xcex1-naphthylmethyl, xcex2-naphthylmethyl, 3-indolylmethyl, 4-imidazolylmethyl, 1,2,3-triazol-1-yl-methyl, 1,2,4-triazol-1-yl-methyl, 2-pyridylmethyl or 4-pyridylmethyl, where functional groups may optionally be protected.
R20 particularly preferably represents hydrogen, C1-C4-alkyl or phenyl.
R19 and R20 together also particularly preferably represent xe2x80x94(CH2)pxe2x80x94, where p=2, 3, 4 or 5, or represent xe2x80x94(CH2)2xe2x80x94NR23xe2x80x94(CH2)2xe2x80x94, where R23 represents C1-C4-alkyl, phenyl or benzyl.
R21 particularly preferably represents hydrogen or C1-C4-alkyl.
R19 and R21 together also particularly preferably represent xe2x80x94(CH2)3xe2x80x94 and xe2x80x94(CH2)4xe2x80x94.
R22 particularly preferably represents hydrogen or a protective group known from peptide chemistry, such as acetyl, tert-butoxycarbonyl, benzyloxycarbonyl or benzyl.
Cxe2x95x90X1, Cxe2x95x90X2, Cxe2x95x90X3 and Cxe2x95x90X4 independently of one another each very particularly preferably represent one of the groups CO or CH2, where at least one of these groups represents CH2.
R1 and R2 independently of one another each very particularly preferably represent methyl, hydroxymethyl or methoxymethyl.
R3 and R4 independently of one another each very particularly preferably represent benzyl which is optionally substituted by a radical W.
R5, R6, R7 and R8 independently of one another each very particularly preferably represent iso-propyl, iso-butyl or sec-butyl.
R9, R10, R11 and R12 each very particularly preferably represent methyl.
W very particularly preferably represents bromine, iodine, nitro, cyano, carbonyl, methoxycarbonyl, ethoxycarbonyl, xe2x80x94CH(R13)NR14R15, 2-oxo-pyrrolidin-5-yl, 2-oxo-piperidin-6-yl, 2-methoxycarbonyl-vinyl, 2-methoxycarbonyl-ethynyl, hydroxyl, methoxy, 2-methoxy-ethoxy, 2-dimethylamino-ethoxy, represents phenyl, benzyl, phenoxy or benzylmethoxy, each of which is optionally mono- or disubstituted independently of one another by fluorine, bromine, nitro, cyano, methyl, ethyl, trifluoromethyl, difluoromethyl, chlorodifluoromethyl, trichloromethyl, methoxy, ethoxy, trifluoromethoxy, hydroxyl or amino, represents 2-furylmethoxy, 2-thienylmethoxy, 2-pyrrolyl-methoxy, xe2x80x94NR16R17 or xe2x80x94SO2xe2x80x94NR16R17.
R13 very particularly preferably represents hydrogen or carboxyl.
R14 very particularly preferably represents hydrogen, acetyl, chloroacetyl or benzoyl.
R15 very particularly preferably represents hydrogen.
R14 and R15, together with the linking nitrogen atom, also very particularly preferably represent 2-oxo-pyrrolidin-1-yl, 2-oxo-piperidin-1-yl, 2-oxo-azepan-1-yl, succinimino, maleinimino, dimethylmaleinimino, glutarimino, phthalimino, tetrafluorophthalimino, 4,5-dichlorophthalimino or tetrachlorophthalimino.
R16 very particularly preferably represents hydrogen, methyl, ethyl, n-propyl, isopropyl, 2-chloroethyl, 2-bromoethyl, 2-chloro-1-propyl, 2-hydroxyethyl, 2-methoxyethyl, 2-furylmethyl, 2-thienylmethyl, 2-pyrrolylmethyl, 2-imidazolylmethyl, formyl, acetyl, propionyl, benzyl, 2-chlorobenzyl, 4-chlorobenzyl, benzoyl, 2-chlorobenzoyl, 4-chlorobenzoyl or 4-nitrobenzoyl or represents the radicals (a) to (1): 
R17 very particularly preferably represents hydrogen or, depending on R16, an identical radical from the group: methyl, ethyl, n-propyl, isopropyl, 2-chloroethyl, 2-bromoethyl, 2-chloro-1-propyl, 2-hydroxyethyl, 2-methoxyethyl, 2-furylmethyl, 2-thienylmethyl, 2-pyrrolylmethyl, 2-imidazolylmethyl, benzyl, 2-chlorobenzyl or 4-chlorobenzyl.
R16 and R17 together also very particularly preferably represent phthaloyl, 3-fluorophthaloyl, 3,4-difluorophthaloyl, 4,5-difluorophthaloyl, 3,6-difluorophthaloyl, tetrafluorophthaloyl, 3-chlorophthaloyl, 4,5-dichlorophthaloyl, tetrachlorophthaloyl, 4-nitrophthaloyl, 3-methylphthaloyl, 4-methylphthaloyl, tetramethylphthaloyl, 4-tert-butylphthaloyl or, together with the linking nitrogen atom, represent an optionally fluorine-, chlorine-, methyl-, ethyl-, n-propyl-, isopropyl-, methoxy- or ethoxy-substituted and optionally n-acetylated monocyclic heterocycle having 5 to 8 ring members or bicyclic heterocycle having 7 to 11 ring members which is optionally bridged, optionally condensed with one or two carbocyclic ring systems, saturated or unsaturated and may contain 1 to 2 further hetero atoms from the group consisting of 1 or 2 nitrogen atoms, 1 oxygen atom and 1 sulfur atom, such as, in particular, morpholinyl, pyrrolyl or piperazinyl.
R19 very particularly preferably represents hydrogen, methyl, iso-propyl, iso-butyl, sec-butyl, hydroxymethyl, 1-hydroxyethyl, mercaptomethyl, 2-methylthioethyl, 3-aminopropyl, 4-aminobutyl, carboxymethyl, 2-carboxyethyl, carbamoylmethyl, 2-carbamoylethyl, 3-guanidinopropyl, phenyl, benzyl, 4-hydroxybenzyl.
R21 very particularly preferably represents hydrogen or methyl.
R22 very particularly preferably represents hydrogen or a protective group known from peptide chemistry, such as acetyl, tert-butoxycarbonyl, benzyloxycarbonyl or benzyl.
Groups of the compounds of the formula (I) which are preferred according to the invention are the compounds of the formulae (I-a) to (I-d) 
Groups of compounds of the formula (I) which are likewise preferred according to the invention are the compounds of the formula (I-1) 
in which
Cxe2x95x90X1, Cxe2x95x90X2, Cxe2x95x90X3 and Cxe2x95x90X4 independently of one another are each as defined further above and
W1 and W2 independently of one another each represent hydrogen or one of the radicals W.
Groups of compounds of the formula (I) which are very particularly preferred according to the invention are the compounds of the formulae (I-1-1), (I-1-2) and (I-1-4) 
in which
W1 and W2 independently of one another each represent hydrogen or one of the radicals W.
Preferably, W1 and W2 represent the same radical.
The abovementioned general or preferred radical definitions or illustrations can be combined with one another as desired, that is to say combinations between the respective ranges and preferred ranges are also possible. They apply both to the end products and, correspondingly, to precursors and intermediates.
Preference according to the invention is given to those compounds of the formula (I) which contain a combination of the definitions listed above as being preferred (preferable).
Particular preference according to the invention is given to those compounds of the formula (I) which contain a combination of the definitions listed above as being particularly preferred.
Very particular preference according to the invention is given to those compounds of the formula (I) which contain a combination of the definitions listed above as being very particularly preferred.
Saturated or unsaturated hydrocarbon radicals such as alkyl or alkenyl, also in combination with hetero atoms, such as, for example, in alkoxy, may in each case, as far as this is possible, be straight-chain or branched.
Optionally substituted radicals may be mono- or polysubstituted, and the substituents in the case of polysubstitutions may be identical or different.
The terms heterocyclyl or hetaryl include, in addition to simple heterocyclic ring systems, also those which are condensed with carbocyclic ring systems.
If, for example, PF 1022A [cf. for example J. Antibiot. 45, 692 (1992)] is reacted with a boron hydride/tetrahydrofuran complex to prepare the compounds according to the invention, the course of the reaction in the process (a) according to the invention can be represented by the following equation: 
If, for example, PF 1022A and [2,4-bis(4-methoxyphenyl)]-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson""s reagent) are employed as starting materials and, in a second reaction step, reacted with sodium borohydride in the presence of nickel chloride, the course of the reaction in the process (b) according to the invention can be represented by the following equation: 
For a further derivatization of the compounds according to the invention, for example PF 1022A which is four-fold reduced is reacted with fuming nitric acid. The course of the reaction can be represented by the following equation: 
The cyclodepsipeptides required for carrying out the processes (a) and (b) according to the invention are known or can be prepared by fermentation and/or synthetically by known methods (cf., for example, EP 382 173 A2, JP 05 229997 A (cited in Derwent AN: 93-317424/40), EP 626 376 A1, EP 634 408 A1, EP 718 293 A1).
The borane furthermore required for carrying out the process (a) can be employed as diborane or as a borane complex such as borane-tetrahydrofuran or borane-dimethyl sulfide (cf. J. Org. Chem. 38, 912 (1973)).
The sulfurizing agent which is, if appropriate, required for carrying out the process (b) is a thionylation reagent, such as, for example, phosphorus pentasulfide or [2,4-bis(4-methoxyphenyl)]-1,3,2,4-dithiadiphosphetane-2,4-dithione (Lawesson""s reagent).
The complex hydrides furthermore required, if appropriate, for carrying out the process (b) are, for example, sodium boronates such as sodium borohydride or sodium cyanoborohydride or lithium alanates such as lithium aluminum hydride.
Further derivatization of the compounds according to the invention is carried out, for example, by the following reactions: alkylation at one or more of the 4 ring nitrogen atoms, nucleophilic or electrophilic aromatic substitution at aromatic radicals, derivatizations of substituents of the aromatic radicals. Aromatic radicals are preferably understood as phenyl or benzyl which, in the formula (I), represent R3 and R4. Particularly preferably, this refers to the introduction, substitution or derivatization of at least one radical W1 and W2 other than hydrogen in compounds of the formula (I-1).
Compounds of the formula (I) according to the invention which are employed for alkylation are those in which at least one of the radicals R9, R11, R10, R12 represents hydrogen and the other radicals and groups have the abovementioned meanings and preferred meanings.
Preference is also given to using compounds of the formula (I) in which at least one of the radicals R3, R4, R5, R6, R7, R8 represents optionally substituted phenyl or benzyl for alkylation. For alkylation, these phenyl or benzyl radicals are substituted by at least one OHxe2x80x94, NH2xe2x80x94, NHR16xe2x80x94 or SH group.
Suitable for use as alkylating agents are the alkylating agents which are customary in organic synthesis such as dialkyl sulfate, in particular C1-4-dialkyl sulfate, optionally substituted alkyl halide, in particular C1-4-alkyl halide, alkyl tosylate, in particular C1-4-alkyl tosylate, alkyl mesylate in particular C1-4-alkyl mesylate.
The alkylation is carried out under the conditions which are customary in organic synthesis (see also the processes described in EP-A 634 408).
Acylations of the OHxe2x80x94, NH2xe2x80x94, NHR16 or SH group can be carried out in a customary manner using
1. Acyl chlorides or carboxylic anhydrides, if appropriate in the presence of bases and solvents
2. Amino acids, which are optionally activated as amino acid fluorides or by coupling with coupling reagents known from peptide chemistry. In these cases, the amino group is protected in a customary manner by protective groups such as, for example, acetyl, t-butyloxycarbonyl or benzyloxycarbonyl. The amino acids can be employed in the form of their racemates or their pure enantiomers (D- or L-form). Preference is given to the L-form of the natural amino acids.
Such amino acids are, for example, amino acids of the formula 
in which
P represents H or the radical of customary protective groups (for example acetyl, Boc, Cbz), and
R19 represents one of the following radicals:
xe2x80x94CH3,
xe2x80x94CH2CH(CH3)2,
xe2x80x94(CH2)4CH3,
xe2x80x94CH(CH3)2,
xe2x80x94(CH2)2CH3,
xe2x80x94C(CH3)3,
xe2x80x94CH2Ph,
xe2x80x94Ph,
xe2x80x94(CH2)2xe2x80x94OH,
xe2x80x94CH(OH)CH3,
xe2x80x94(CH2)2SCH3,
xe2x80x94(CH2)2CONH2,
xe2x80x94CH2xe2x80x94CO2H, 
In the above formula for amino acids, P and R19 together may represent one of the following divalent radicals
xe2x80x94(CH2)3xe2x80x94
xe2x80x94(CH2)4xe2x80x94.
Nucleophilic aromatic substitution preferably means the substitution of fluorine, chlorine, bromine, iodine, nitro by halides, alkoxides or primary or secondary amines or metal amides thereof. Furthermore, the term also includes the substitution of diazo groups, including, depending on reaction conditions and nucleophile, even radical substitution. Examples include the diazotization and subsequent hydrolysis in aqueous acid to give the phenol derivative or, using sulfur nucleophiles, to give the thiophenol derivative or sufide, undiluted in the presence of fluoride or tetrafluoroborate as nucleophile (Balzxe2x80x94Schiemann reaction), and under Sandmeyer conditions, for example using copper(I) halides or cyanide.
The nucleophilic aromatic substitution is preferably carried out using compuonds of the formula (I) according to the invention in which at least one of the radicals R3, R4, R5, R6, R7, R8 represents substituted phenyl or benzyl.
For nucleophilic substitution, these phenyl or benzyl radicals are substituted by fluorine, chlorine, bromine, iodine or nitro. They are preferably reacted with optionally substituted C1-4-alkoxides or primary or secondary amines of the formula HNR16R17 in which R16 and R17 are each as defined above, or with metal amides.
The reaction is carried out by generally known methods of organic chemistry.
The diazotization and subsequent hydrolysis to give the corresponding phenols, thiophenols or sulfides and reactions of the type of the Balz-Schiemann or Sandmeyer reaction are carried out using compounds of the formula (I) in which at least one of the radicals R3 to R8 represents optionally substituted phenyl or benzyl, where at least one of these phenyl or benzyl radicals is substituted by amino. Such compounds are obtained according to the process described, for example, in EP-A 634 408, by nitration of the unsubstituted compounds and subsequent reduction of the nitro group to give the amino group.
Electrophilic aromatic substitution preferably means nitration, amidoalkylation, sulfurization, sulfochlorination, sulfonylation, bromination, iodination, Friedel-Crafts acylation and Friedel-Crafts alkylation.
The electrophilic aromatic substitution is carried out using compounds of the formula (I) in which at least one of the radicals R3 to R8 represents phenyl or benzyl. The practice of these substitutions is described, for example, in EP-A 634 408 and WO 95/3926. The details given therein with regard to starting materials, reactions and reaction conditions are expressly referred to.
Further derivatization of substituents of the aromatic radicals is carried out by reactions and under reaction conditions which are known from organic chemistry. Examples include: palladium-catalyzed alkenylation and alkynylation, reduction of a nitro group to give an amino group, alkylation of an amino group, in particular monoalkylation using a bifunctional alkylating reagent, followed by intramolecular alkylation to give a heterocyclic radical of the formula xe2x80x94NR16R17, alkylation of a hydroxyl group, oxidation of an alkylthio group to give the sulfoxide or sulfone.
The active compounds are suitable for controlling pathogenic endoparasites encountered in humans and in animal husbandry and livestock breeding, in productive livestock, breeding stock, zoo animals, laboratory animals, animals used in experiments, and pets, and have low toxicity toward warm-blooded animals. They are active against resistant and normally sensitive species and against all or some stages of development of the pests. By controlling the pathogenic endoparasites, it is intended to reduce disease, mortality and decreasing performance (for example in the production of meat, milk, wool, hides, eggs, honey, etc.), so that more economical and simpler animal keeping is possible by using the active compounds. The pathogenic endoparasites include Cestodes, Trematodes, Nematodes, in particular:
From the order of the Pseudophyllidea, for example Diphyllobothrium spp., Spirometra spp., Schistocephalus spp., Ligula spp., Bothridium spp., Diphlogonoporus spp.
From the order of the Cyclophyllidea, for example Mesocestoides spp., Anoplocephala spp., Paranoplocephala spp., Moniezia spp., Thysanosomsa spp., Thysaniezia spp., Avitellina spp., Stilesia spp., Cittotaenia spp., Andyra spp., Bertiella spp., Taenia spp., Echinococcus spp., Hydratigera spp., Davainea spp., Raillietina spp., Hymenolepis spp., Echinolepis spp., Echinocotyle spp., Diorchis spp., Dipylidium spp., Joyeuxiella spp., Diplopylidium spp.
From the subclass of the Monogenea, for example Gyrodactylus spp., Dactylogyrus spp., Polystoma spp.
From the subclass of the Digenea, for example Diplostomum spp., Posthodiplostomum spp., Schistosoma spp., Trichobilharzia spp., Omithobilharzia spp., Austrobilharzia spp., Gigantobilharzia spp., Leucochloridium spp., Brachylaima spp., Echinostoma spp., Echinoparyphium spp., Echinochasmus spp., Hypoderaeum spp., Fasciola spp., Fasciolides spp., Fasciolopsis spp., Cyclocoelum spp., Typhloccelum spp., Paramphistomum spp., Calicophoron spp, Cotylophoron spp., Gigantocotyle spp., Fischoederius spp., Gastrothylacus spp., Notocotylus spp., Catatropis spp., Plagiorchis spp., Prosthogonismus spp., Dicrocoelium spp., Collyriclum spp., Nanophyetus spp., Opisthorchis spp., Clonorchis spp., Metorchis spp., Heterophyes spp., Metagonimus spp.
From the order of the Enoplida, for example Trichuris spp., Capillaria spp., Trichlomosoides spp., Trichinella spp.
From the order of the Rhabditida, for example Micronema spp., Strongyloides spp. From the order of the Strongylida, for example Stronylus spp., Triodontophorus spp., Oesophagodontus spp., Trichonema spp., Gyalocephalus spp., Cylindropharynx spp., Poteriostromum spp., Cyclococercus spp., Cylicostephanus spp., Oesophagostomum spp., Chabertia spp., Stephanurus spp., Ancylostoma spp., Uncinaria spp., Bunostomum spp., Globocephalus spp., Syngamus spp., Cyathostoma spp., Metastrongylus spp., Dictyocaulus spp., Muellerius spp., Protostrongylus spp., Neostrongylus spp., Cystocaulus spp., Pneumostrongylus spp., Spicocaulus spp., Elaphostrongylus spp., Parelaphostrongylus spp., Crenosoma spp., Paracrenosoma spp., Angiostrongylus spp., Aelurostrongylus spp., Filaroides spp., Parafilaroides spp., Trichostrongylus spp., Haemonchus spp., Ostertagia spp., Marshallagia spp., Cooperia spp., Nematodirus spp., Hyostrongylus spp., Obeliscoides spp., Amidostomum spp., Ollulanus spp.
From the order of the Oxyurida, for example Oxyuris spp., Enterobius spp., Passalurus spp., Syphacia spp., Aspiculuris spp., Heterakis spp.
From the order of the Ascaridia, for example Ascaris spp., Toxascaris spp., Toxocara spp., Parascaris spp., Anisakis spp., Ascaridia spp.
From the order of the Spirurida, for example Gnathostoma spp., Physaloptera spp., Thelazia spp., Gongylonema spp., Habronema spp., Parabronema spp., Draschia spp., Dracunculus spp.
From the order of the Filariida, for example Stephanofilaria spp., Parafilaria spp., Setaria spp., Loa spp., Dirofilaria spp., Litomosoides spp., Brugia spp., Wuchereria spp., Onchocerca spp.
From the group of the Gigantorhynchida, for example Filicollis spp., Moniliformis spp., Macracanthorhynchus spp., Prosthenorchis spp.
The active compounds according to the invention have, for example, outstanding activity against worms such as Haemonchus contortus. 
The livestock and breeding stock include mammals, such as, for example, cattle, horses, sheep, pigs, goats, camels, water buffalo, donkeys, rabbits, fallow deer, reindeer, fur-bearing animals, such as, for example, minks, chinchilla or racoon, birds, such as, for example chickens, geese, turkeys or ducks, freshwater fish and sea fish, such as, for example, trout, carp and eels, reptiles and insects, such as, for example, honeybee and silkworm.
The laboratory and test animals include mice, rats, guinea pigs, golden hamsters, dogs and cats.
The pets include dogs and cats.
Administration can be effected prophylactically as well as therapeutically.
The active substances are administered, either directly or in the form of suitable preparations, enterally, parenterally, dermally, nasally, by treating the habitat or with the aid of shaped articles containing the active compound, such as, for example, strips, plates, tapes, collars, ear tags, limb bands or marking devices.
Enteral administration of the active compounds is effected for example orally in the form of powders, suppositories, tablets, capsules, pastes, drinks, granules, solutions, suspensions and emulsions which can be applied orally, boluses, medicated feed or drinking water. Dermal application is effected, for example, in the form of dipping, spraying, bathing, washing, pouring-on and spotting-on, and powdering. Parenteral administration is effected, for example, in the form of injection (intramuscular, subcutaneous, intravenous or intraperitoneal) or by implants.
Suitable preparations include:
Solutions, such as solutions for injection, oral solutions, concentrates for oral administration after dilution, solutions for use on the skin or in body cavities, pour-on formulations, gels;
Emulsions and suspensions for oral or dermal administration and for injection; semisolid preparations;
Formulations in which the active compound is incorporated in a cream base or in an oil-in-water or water-in-oil emulsion base;
Solid preparations, such as powders, premixes or concentrates, granules, pellets, tablets, boluses, capsules; aerosols and inhalants, shaped articles containing the active compound.
Solutions for injection are administered intravenously, intramuscularly and subcutaneously.
Solutions for injection are prepared by dissolving the active compound in a suitable solvent and, if desired, adding additives, such as solubilizers, acids, bases, buffer salts, antioxidants, or preservatives. The solutions are sterile-filtered and decanted into containers.
Suitable solvents include: physiologically acceptable solvents, such as water, alcohols, such as ethanol, butanol, benzyl alcohol, glycerol, hydrocarbons, propylene glycol, polyethylene glycols and N-methylpyrrolidone, and their mixtures.
If appropriate, the active compounds can also be dissolved in physiologically acceptable vegetable or synthetic oils which are suitable for injection.
Suitable solubilizers include: solvents which facilitate the dissolution of the active compound in the main solvent or which prevent precipitation of the active compound. Examples of solubilizers are polyvinylpyrrolidone, polyethoxylated castor oil and polyethoxylated sorbitan esters.
The following are preservatives: benzyl alcohol, trichlorobutanol, p-hydroxybenzoic esters or n-butanol.
Oral solutions are administered directly. Concentrates are first diluted to the administration concentration and then administered orally. Oral solutions and concentrates are prepared as described above in the case of the solutions for injection, sterile procedures not being necessary.
Solutions for use on the skin are applied drop by drop, smoothed on, rubbed in, splashed on or sprayed on, or applied by dipping, bathing or washing. These solutions are prepared as described above in the case of the solutions for injection.
It may be advantageous to add thickeners in the preparation process.
The following are thickeners: inorganic thickeners, such as bentonites, colloidal silica, aluminum monostearate, or organic thickeners, such as cellulose derivatives, polyvinyl alcohols and their copolymers, acrylates and methacrylates.
Gels are applied to the skin or smoothed on or introduced into body cavities. Gels are prepared by adding such an amount of thickener to solutions which have been prepared as described for the solutions for injection that a clear composition is formed which has an ointment-like consistency. The thickeners used are the thickeners indicated further above.
Pour-on and spot-on formulations are poured or splashed onto limited areas of the skin, the active compound penetrating the skin and acting systemically or distributing itself over the surface of the body.
Pour-on and spot-on formulations are prepared by dissolving, suspending or emulsifying the active compound in suitable solvents or solvent mixtures which are tolerated by the skin. If appropriate, other auxiliaries, such as colorants, absorption promoters, antioxidants, photostabilizers or tackifiers are added.
Suitable solvents include: water, alkanols, glycols, polyethylene glycols, polypropylene glycols, glycerol, aromatic alcohols, such as benzyl alcohol, phenylethanol or phenoxyethanol, esters, such as ethyl acetate, butyl acetate or benzyl benzoate, ethers, such as alkylene glycol alkyl ethers, such as dipropylene glycol monomethyl ether or diethylene glycol mono-butyl ether, ketones, such as acetone or methyl ethyl ketone, aromatic and/or aliphatic hydrocarbons, vegetable or synthetic oils, DMF, dimethyl acetamide, N-methylpyrrolidone, or 2,2-dimethyl-4-oxy-methylene-1,3-dioxolane.
Colorants are all colorants which can be dissolved or suspended and which are approved for use in animals.
Examples of bioabsorption promoters are DMSO, spreading oils, such as isopropyl myristate, dipropylene glycol pelargonate, silicone oils, fatty acid esters, triglycerides or fatty alcohols.
The following are antioxidants: sulfites or metabisulfites, such as potassium metabisulfite, ascorbic acid, butylhydroxytoluene, butylhydroxyanisole or tocopherol.
Example of photostabilizers are substances from the class of the benzophenones or novantisolic acid.
Tackifiers are, for example, cellulose derivatives, starch derivatives, polyacrylates or natural polymers such as alginates or gelatin.
Emulsions can be administered orally, dermally or as injections.
Emulsions are either the water-in-oil type or the oil-in-water type.
They are prepared by dissolving the active compound either in the hydrophobic or in the hydrophilic phase and by homogenizing this phase with the solvent of the other phase, with the aid of suitable emulsifiers and, if appropriate, other auxiliaries, such as colorants, bioabsorption promoters, preservatives, antioxidants, photostabilizers, and viscosity-increasing substances.
Suitable hydrophobic phases (oils) include: paraffin oils, silicone oils, natural vegetable oils such as sesame seed oil, almond oil or castor oil, synthetic triglycerides, such as caprylic/capric acid biglyceride, a triglyceride mixture with vegetable fatty acids of chain length C8-12 or other specifically selected natural fatty acids, mixtures of partial glycerides of saturated or unsaturated fatty acids which may also contain hydroxyl groups, and mono- and diglycerides of the C8/C10-fatty acids.
Fatty acid esters, such as ethyl stearate, di-n-butyryl adipate, hexyl laurate, dipropylene glycol pelargonate, esters of a branched fatty acid having a medium chain length with saturated fatty alcohols of chain length C16-C18, isopropyl myristate, isopropyl palmitate, caprylic/capric esters of saturated fatty alcohols of chain length C12-C18, isopropyl stearate, oleyl oleate, decyl oleate, ethyl oleate, ethyl lactate, waxy fatty acid esters such as artificial duck uropygial fat, dibutyl phthalate, diisopropyl adipate, ester mixtures related to the latter, etc.
Fatty alcohols, such as isotridecyl alcohol, 2-octyldodecanol, cetylstearyl alcohol or oleyl alcohol.
Fatty acids, such as, for example, oleic acid and its mixtures.
Suitable hydrophilic phases include:
water, alcohols, such as, for example, propylene glycol, glycerol, sorbitol and their mixtures.
Suitable emulsifiers include:
nonionic surfactants, for example polyethoxylated castor oil, polyethoxylated sorbitan monooleate, sorbitan monostearate, glycerol monostearate, polyoxyethyl stearate or alkylphenol polyglycol ethers;
ampholytic surfactants, such as disodium N-lauryl-xcex2-iminodipropionate or lecithin;
anionic surfactants, such as Na lauryl sulfate, fatty alcohol ether sulfates, and the monoethanolamine salt of mono/dialkylpolyglycol ether orthophosphoric ester;
cationic surfactants, such as cetyltrimethylammonium chloride.
Other suitable auxiliaries include: substances which increase the viscosity and stabilize the emulsion, such as carboxymethylcellulose, methylcellulose and other cellulose and starch derivatives, polyacrylates, alginates, gelatin, gum arabic, polyvinyl-pyrrolidone, polyvinyl alcohol, methylvinyl ether/maleic anhydride copolymers, polyethylene glycols, waxes, colloidal silica, or mixtures of the listed substances.
Suspensions can be administered orally, dermally or as an injection. They are prepared by suspending the active compound in a liquid excipient, if appropriate with the addition of other auxiliaries, such as wetting agents, colorants, bioabsorption promoters, preservatives, antioxidants and photostabilizers.
Suitable liquid excipients include all homogeneous solvents and solvent mixtures.
Suitable wetting agents (dispersants) include the surfactants indicated further above.
Suitable other auxiliaries include those indicated further above.
Semi-solid preparations can be administered orally or dermally. They are only distinguished from the above-described suspensions and emulsions by their higher viscosity.
To prepare solid preparations, the active compound is mixed with suitable excipients, if appropriate with the addition of auxiliaries, and the mixture is formulated as desired.
Suitable excipients include all physiologically acceptable solid inert substances. Suitable for this purpose are inorganic and organic substances. Inorganic substances are, for example, common salt, carbonates, such as calcium carbonate, hydrogen carbonates, aluminum oxides, silicas, clays, precipitated or colloidal silica, and phosphates.
Organic substances are, for example, sugars, cellulose, foodstuffs and animal feeds, such as powdered milk, animal meals, cereal meals, coarse cereal meals and starches.
Auxiliaries are preservatives, antioxidants and colorants which have already been mentioned further above.
Other suitable auxiliaries are lubricants and glidants, such as, for example, magnesium stearate, stearic acid, talc, bentonites, disintegrants, such as starch or crosslinked polyvinylpyrrolidone, binders, such as, for example, starch, gelatin or linear polyvinylpyrrolidone, and dry binders, such as microcrystalline cellulose.
In the preparations, the active compounds can also be present in mixtures with synergists or other active compounds which are active against pathogenic endoparasites. Examples of such active compounds are L-2,3,5,6-tetrahydro-6-phenylimidazolethiazole, benzimidazole carbamates, praziquantel, pyrantel or febantel.
Ready-to-use preparations contain the active compound in concentrations of 10 ppm to 20% by weight, preferably from 0.1 to 10% by weight.
Preparations which are diluted before use contain the active compound in concentrations of 0.5 to 90% by weight, preferably from 5 to 50% by weight.
In general, it has been found to be advantageous to administer amounts of about 1 to 100 mg of active compound per kg of bodyweight per day to obtain effective results.
The preparation and the use of the active compounds according to the invention can be seen from the examples below.